Sol-gel derived calcium silicates are of great importance due to their ability to bond to bone and stimulate new bone growth. Diffraction has revealed the atomic-scale changes as a function of heat-treatment, which is an essential stage in materials processing and during which the H content of the original xerogel decreases significantly. Additionally, SAXS data has shown that these materials undergo structural changes upon heat treatment at longer length scales. We therefore propose to study the structure of sol-gel derived (CaO)0.3(SiO2)0.7 as a function of temperature using NIMROD in order to elucidate these changes at all length scales simultaneously and therefore to be able to ensure registry between all regions of the data. Furthermore, NIMROD will augment the SAXS data by virtue of its enhanced sensitivity to residual hydrogen.